Downhole tool with a dissolvable component

Abstract

A downhole tool and a method for fracturing a well, of which the method includes running downhole tool into a wellbore, the downhole tool including a ball seat including a dissolvable material and a protective layer that substantially prevents the dissolvable material from dissolving, and deploying an obstructing member into the wellbore. The obstructing member is caught by the ball seat. The method also includes performing one or more fracturing operations while the obstructing member engages the ball seat. Performing the one or more fracturing operations comprises introducing an abrading fluid to the ball seat, and the abrading fluid erodes at least a portion of the protective layer from the ball seat. The method also includes, after eroding the at least a portion of the protective layer, causing the dissolvable material of the ball seat to at least partially dissolve.

What is claimed is: 
     
         1 . A method for fracturing a well, comprising:
 running downhole tool into a wellbore, the downhole tool comprising a ball seat including a dissolvable material and a protective layer that substantially prevents the dissolvable material from dissolving;   deploying an obstructing member into the wellbore, wherein the obstructing member is caught by the ball seat;   performing one or more fracturing operations while the obstructing member engages the ball seat, wherein performing the one or more fracturing operations comprises introducing an abrading fluid to the ball seat, and wherein the abrading fluid erodes at least a portion of the protective layer from the ball seat; and   after eroding the at least a portion of the protective layer, causing the dissolvable material of the ball seat to at least partially dissolve.   
     
     
         2 . The method of  claim 1 , wherein the abrading fluid comprises frac sand, proppant, or both. 
     
     
         3 . The method of  claim 1 , wherein the abrading fluid dissolves the dissolvable material after the protective layer is eroded. 
     
     
         4 . The method of  claim 1 , wherein performing the one or more fracturing operations comprises injecting the abrading fluid into a formation. 
     
     
         5 . The method of  claim 1 , wherein the protective layer comprises a treated outer layer of the ball seat. 
     
     
         6 . The method of  claim 5 , wherein the treated outer layer comprises an oxide of the dissolvable material. 
     
     
         7 . The method of  claim 1 , wherein the protective layer comprises a coating applied to the ball seat. 
     
     
         8 . The method of  claim 7 , wherein the coating comprises a polymer. 
     
     
         9 . The method of  claim 1 , wherein the protective layer comprises:
 a treated outer layer of the ball seat; and   a protective coating applied to the treated outer layer of the ball seat.   
     
     
         10 . The method of  claim 1 , wherein the dissolvable material comprises a dissolvable material matrix comprising at least one of cast iron, ceramic powder, sand, and carbide. 
     
     
         11 . The method of  claim 10 , wherein the dissolvable material matrix further comprises magnesium, thermoplastic, aluminum, or a combination thereof. 
     
     
         12 . A downhole tool, comprising:
 a dissolvable component comprising a dissolvable material and at least one protective outer layer at least partially enveloping the dissolvable material, wherein the at least one protective outer layer is configured to be eroded by an abrading fluid so as to allow introduction of the abrading fluid to the dissolvable material, wherein the dissolvable material dissolves in the presence of the abrading fluid.   
     
     
         13 . The downhole tool of  claim 12 , further comprising a body defining a bore therethrough, wherein the dissolvable component comprises a ball seat positioned within the bore of the body, the ball seat being configured to catch an obstructing member, so as to plug the bore of the body. 
     
     
         14 . The downhole tool of  claim 12 , wherein the body defines one or more openings therein, and wherein the ball seat catching the obstructing member causes the one or more openings to allow fluid communication from a bore of the body to an exterior of the tool. 
     
     
         15 . The downhole tool of  claim 14 , wherein the body comprises an outer housing defining a first opening of the one or more openings, and an inner mandrel positioned within the outer housing and defining a second opening of the one or more openings, the downhole tool further comprising a sliding sleeve positioned between the inner mandrel and the outer housing, wherein the sliding sleeve is slidable between a first position in which the slidable sleeve prevents fluid communication between the first and second openings, and a second position in which the slidable sleeve permits fluid communication between the first and second openings. 
     
     
         16 . The downhole tool of  claim 12 , wherein the at least one protective layer comprises a treated outer surface layer of the dissolvable material, and wherein the treated outer surface layer comprises an oxide of the dissolvable material, wherein the oxide is not dissolvable in a fluid configured to dissolve the dissolvable material. 
     
     
         17 . The downhole tool of  claim 12 , wherein the at least one protective layer comprises a polymer. 
     
     
         18 . The downhole tool of  claim 12 , wherein the dissolvable material comprises a matrix including magnesium, a thermoplastic, or a combination thereof, and cast iron, a ceramic, sand, a carbide, or a combination thereof. 
     
     
         19 . The downhole tool of  claim 12 , wherein the dissolvable component comprises a mandrel, the tool further comprising a setting assembly and one or more seals positioned around the mandrel. 
     
     
         20 . A method of removing a component in a wellbore, the method comprising:
 deploying the component into the wellbore, the component comprising a dissolvable material and a protective layer at least partially enveloping the dissolvable material, wherein the protective layer substantially prevents the dissolvable material from dissolving until the protective layer is at least partially removed by an abrading fluid;   pumping the abrading fluid into the wellbore to remove at least a portion the protective layer of the component; and   removing the component by dissolving the dissolvable material exposed by removing the at least a portion of the protective layer.   
     
     
         21 . The method of  claim 20 , wherein the component is a ball or a dart.